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Old 21st Oct 2021, 4:43 pm   #141
Mark1960
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Default Re: Commodore PET 2001 voltage regulators

Did you try without UD5 fitted? A bad chip could pull the data bus signals to false levels.
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Old 21st Oct 2021, 5:03 pm   #142
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Default Re: Commodore PET 2001 voltage regulators

Quote:
Originally Posted by Mark1960 View Post
Did you try without UD5 fitted? A bad chip could pull the data bus signals to false levels.
Hi. Yes, after cleaning the sockets (and seeing the damage to the UD5 chip) I tried switching the PET on again (with just the 4 PROMS seated) - it just displayed the garbled screen.

The chip is staying out of the PET as one of the legs has already come off, and there are a couple of others that are a bit wobbly.

Tim.
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Old 21st Oct 2021, 5:12 pm   #143
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Default Re: Commodore PET 2001 voltage regulators

Post # 5 of this German forum thread appears to have the binary code content of this PROM, which is a relief, otherwise my mind would have been buzzing over ways to save yours.

https://forum.classic-computing.de/f...power-rom-pac/

You could file into the sides of the chip where the pins came off to reveal a sliver of clean metal to solder to, solder very fine wires (single strands from a piece of multistrand wire) to the metal remains of the missing pins, plug the PROM into a conventional (not turned pin) 24 pin socket and tack solder the other ends of the fine wires to the socket receptacles that the pins would be going to if they were still there.

Plug that combination (PROM plus added socket, with its 24 good pins) into your programmer and see if you can read it as a TMS2532 if your programmer supports that device.

But anyway... that's an interesting but separate issue to getting the machine working - let's let Tim get his scope, by which time he should also have the test PROMs, and we will be able to get going on this.
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Old 21st Oct 2021, 5:31 pm   #144
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Default Re: Commodore PET 2001 voltage regulators

I'd certainly be interested in a dump of that ROM.

Tim: What was the link to the information you found? Was there a ROM image there?
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Old 21st Oct 2021, 5:37 pm   #145
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Default Re: Commodore PET 2001 voltage regulators

Quote:
Was there a ROM image there?
See post #143
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Old 21st Oct 2021, 5:38 pm   #146
retromit
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Default Re: Commodore PET 2001 voltage regulators

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Originally Posted by Slothie View Post
I'd certainly be interested in a dump of that ROM.

Tim: What was the link to the information you found? Was there a ROM image there?

Hi. The link I found is below:

https://datassette.nyc3.cdn.digitalo...it_for_pet.pdf

It was just a PDF of the toolkit manual.

Tim.
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Old 21st Oct 2021, 5:40 pm   #147
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Default Re: Commodore PET 2001 voltage regulators

Another source for the manual in various forms here:-

https://archive.org/details/The_Basi...oolkit_for_PET
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Old 21st Oct 2021, 5:43 pm   #148
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Default Re: Commodore PET 2001 voltage regulators

Quote:
Originally Posted by SiriusHardware View Post
Quote:
Was there a ROM image there?
See post #143
Ah! Got lost in the time vortex
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Old 21st Oct 2021, 5:56 pm   #149
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Default Re: Commodore PET 2001 voltage regulators

Try installing it in VICE (Commodore emulator program) - see what it does?
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Old 21st Oct 2021, 5:58 pm   #150
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Default Re: Commodore PET 2001 voltage regulators

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Originally Posted by SiriusHardware View Post
Try installing it in VICE (Commodore emulator program) - see what it does?
Yeh I was going to.... To download it you have to join the forum, I tried that and to join you have to click a link in the verification email which hasn't arrived yet! I'm sure it will someday....
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Old 21st Oct 2021, 6:14 pm   #151
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Default Re: Commodore PET 2001 voltage regulators

OK, go to the 'other firmware' section of the zimmerman site:-

http://www.zimmers.net/anonftp/pub/c...her/index.html

..and look for these two files

Quote:
toolkit-b000.bin2009-08-182048
toolkit-b000.txt2009-08-181324

Description:

"The BASIC Programmer's Toolkit (3032 version). Adds new commands to
PET's BASIC interpreter".
The .txt file show exactly the same set of added commands as the manuals referenced above so I think this is probably the same utility. There are lots of other 'toolkit' ROM images in that area as well.
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Old 21st Oct 2021, 7:13 pm   #152
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Default Re: Commodore PET 2001 voltage regulators

Yes, that seems to be the ROM that TIM has because of the copyright message when you activate it.

https://youtu.be/VliXpd-bu8s
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Old 21st Oct 2021, 7:17 pm   #153
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Default Re: Commodore PET 2001 voltage regulators

Good, so if Tim eventually wants to get that additional functionality back he can have that code programmed into a TMS2532 to go into the UD5 position.

Some of what it adds in are things we would consider 'standard' for slightly later BASICs, like Auto line numbering and line renumbering. Well worth putting back in eventually.

The machine will need to work first, though.
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Old 21st Oct 2021, 7:19 pm   #154
retromit
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Default Re: Commodore PET 2001 voltage regulators

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Originally Posted by Slothie View Post
Yes, that seems to be the ROM that TIM has because of the copyright message when you activate it.

https://youtu.be/VliXpd-bu8s
That's great news that the image works. I'm going to go ahead with what SiriusHardware suggested with regards to socketing the ROM and trying to attach a wire as the leg. If I can get this working, then I've a TL866 II programmer and I'll try and read the ROM. If it works, then I can check it against the one you have downloaded and make this available if anyone else wants it.
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Old 21st Oct 2021, 7:25 pm   #155
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Default Re: Commodore PET 2001 voltage regulators

Do that, but be aware that your programmer needs to have the specific ability to read Texas Instruments TMS2532s (not 2732s, which have a slightly different pinout). You could do it with a programmer which can read 2732s, but only if you make an adaptor to rearrange the wiring of pin 18 / pin 21.

If you can actually directly read TMS2532s then please also read the contents of UD6 through to UD9 and save their code as appropriately named .bin files.

Last edited by SiriusHardware; 21st Oct 2021 at 7:41 pm.
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Old 21st Oct 2021, 10:16 pm   #156
retromit
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Default Re: Commodore PET 2001 voltage regulators

Quote:
Originally Posted by SiriusHardware View Post
Do that, but be aware that your programmer needs to have the specific ability to read Texas Instruments TMS2532s (not 2732s, which have a slightly different pinout). You could do it with a programmer which can read 2732s, but only if you make an adaptor to rearrange the wiring of pin 18 / pin 21.

If you can actually directly read TMS2532s then please also read the contents of UD6 through to UD9 and save their code as appropriately named .bin files.
Right, I managed to get the UD5 chip (BASIC toolkit) into a socket and soldered a wire for the leg. Testing the continuity on this, it was fine. Following your advice, I checked the EPROM programmer I have, and it will not read TMS2532s, but will read TMS2732As. I found the following information in post #18 on https://atariage.com/forums/topic/27...om-programmer/

So I built the adapter (not the prettiest), checking all continuity between between the pins; all, again, was fine. When using the programmer, and setting it to read using a TMS2732A as the template, it passes the tests, but just returns FF for every address, with no ASCII text. So it looks like there could be an issue with the adapter (although all the pins in the continuity test are correct), the programmer just doesn't want to read it, or there is an issue with the chip (with it being initially corroded and the leg falling off - plus a couple of the other legs are wobbly).

I'll have a look over it again tomorrow, but thought I'd let you know. At the very worse, it looks like a new EPROM can be programmed with the image file found previously, but it could also be worth testing the chip/socket (to see if the leg fix worked) when the PET is finally running again.
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Old 21st Oct 2021, 10:17 pm   #157
retromit
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Default Re: Commodore PET 2001 voltage regulators

I suppose I could always just remove one of the other chips from UD6 - UD9 and see if they can be read. Didn't think of that at the time.
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Old 21st Oct 2021, 10:20 pm   #158
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Default Re: Commodore PET 2001 voltage regulators

If you want to have a go, here is how to connect a 2332 PROM to your EPROM programmer so it can be read as if it is a 2732. The easiest way to make such an adaptor is to stack two or more IC sockets one on top of the other, break the connections between PROM pin 18 / reader pin 18 and PROM pin 21 / reader pin 21 as they pass down through the stack, re-route PROM pin 18 to reader pin 21 and re-route PROM pin 21 to reader pin 24 - but, leave the connection between PROM pin 24 and reader pin 24 intact.

If you do this take extreme care to put the PROM in the adaptor and the adaptor in the reader the right way around and do not inadvertently invoke the programming mode of the reader / programmer as it will seriously damage the PROM.

Edit: Tim built an adaptor in less time than it took me to describe it The wiring in mine is simpler because it is only for READING, which is the only thing you can actually do with a PROM (the programming in them was fixed at the factory).
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Old 21st Oct 2021, 10:27 pm   #159
retromit
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Default Re: Commodore PET 2001 voltage regulators

Quote:
Originally Posted by SiriusHardware View Post
If you want to have a go, here is how to connect a 2332 PROM to your EPROM programmer so it can be read as if it is a 2732. The easiest way to make such an adaptor is to stack two or more IC sockets one on top of the other, break the connections between PROM pin 18 / reader pin 18 and PROM pin 21 / reader pin 21 as they pass down through the stack, re-route PROM pin 18 to reader pin 21 and re-route PROM pin 21 to reader pin 24 - but, leave the connection between PROM pin 24 and reader pin 24 intact.

If you do this take extreme care to put the PROM in the adaptor and the adaptor in the reader the right way around and do not inadvertently invoke the programming mode of the reader / programmer as it will seriously damage the PROM.

Edit: Tim built an adaptor in less time than it took me to describe it
Can I just check something? Should it be a 2532 (which is being read) rather than the 2332 (or are they pin compatible)?

Last edited by retromit; 21st Oct 2021 at 10:39 pm.
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Old 21st Oct 2021, 10:44 pm   #160
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Default Re: Commodore PET 2001 voltage regulators

The TMS2532 is the EPROM equivalent of the non-reprogrammable 2332 PROM, so in read mode they should both look exactly the same to the reader.

It sounds to me as though the adaptor you have made is to 'rewire' a TMS2532 so that it can be programmed with a TMS2732 programmer as well as read with one. (My adaptor only allows for reading).
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